<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><head><title>R: Data from the National Wilm's Tumor Study</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link rel="stylesheet" type="text/css" href="R.css">
</head><body>

<table width="100%" summary="page for nwtco"><tr><td>nwtco</td><td align="right">R Documentation</td></tr></table>

<h2>Data from the National Wilm's Tumor Study</h2>

<h3>Description</h3>


<p>Missing data/masurement error example. Tumor histology predicts
survival, but prediction is stronger with central lab histology than
with the local institution determination.
</p>


<h3>Usage</h3>

<pre>nwtco</pre>


<h3>Format</h3>


<p>A data frame with 4028 observations on the following 9 variables.
</p>

<dl>
<dt><code>seqno</code></dt><dd><p>id number</p>
</dd>
<dt><code>instit</code></dt><dd><p>Histology from local institution</p>
</dd>
<dt><code>histol</code></dt><dd><p>Histology from central lab</p>
</dd>
<dt><code>stage</code></dt><dd><p>Disease stage</p>
</dd>
<dt><code>study</code></dt><dd><p>study</p>
</dd>
<dt><code>rel</code></dt><dd><p>indicator for relapse</p>
</dd>
<dt><code>edrel</code></dt><dd><p>time to relapse</p>
</dd>
<dt><code>age</code></dt><dd><p>age in months</p>
</dd>
<dt><code>in.subcohort</code></dt><dd><p>Included in the subcohort for the example in the
paper</p>
</dd>
</dl>



<h3>Source</h3>


<p><a href="http://faculty.washington.edu/norm/software.html">http://faculty.washington.edu/norm/software.html</a>
</p>


<h3>References</h3>


<p>NE Breslow and N Chatterjee (1999),
Design and analysis of two-phase studies with binary outcome applied
to Wilms tumour prognosis.
<EM>Applied Statistics</EM> <B>48</B>, 457&ndash;68.
</p>


<h3>Examples</h3>

<pre>
with(nwtco, table(instit,histol))
anova(coxph(Surv(edrel,rel)~histol+instit,data=nwtco))
anova(coxph(Surv(edrel,rel)~instit+histol,data=nwtco))
</pre>


</body></html>
